KR19980040332A - Liquid crystal display element - Google Patents

Abstract

The present invention discloses a liquid crystal display device capable of effectively preventing static electricity.

The disclosed invention includes a thin film transistor formed at an intersection of a gate line, a data line perpendicular to the gate line, a gate line and a data line, a pixel electrode connected to a drain electrode of the thin film transistor, A liquid crystal display device formed on a same lower substrate of a counter electrode positioned at a distance separated by an area through which light is transmitted, comprising: a lower substrate; A first polarizer formed on a rear surface of the lower substrate; An upper substrate facing the lower substrate; An antistatic conductive film formed on the upper substrate; And a second polarizing plate formed on the upper substrate on which the conductive film is formed.

Description

Liquid crystal display element

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device that can prevent static electricity.

In general, liquid crystal display elements constitute display elements such as televisions and graphic displays, and especially active matrix type liquid crystal display devices have high-speed response characteristics, and are suitable for high pixel counts, thereby making display screens of high quality, large size, and color screens. It greatly contributes to the realization of money.

The liquid crystal display device includes a pair of transparent glass substrates, thin film transistors and pixel electrodes formed on at least one substrate, a color filter and a counter electrode formed on the other substrate, and a liquid crystal material between the pair of glass substrates. This is done by encapsulation.

Here, as the liquid crystals used in recent years, a twist nematic mode (hereinafter, referred to as TN) liquid crystal having excellent optical characteristics is used, and the twisted nematic mode has a twist angle of 90 °, and the liquid crystal molecules are upper and lower glass. Since the array is arranged parallel to the substrate plane or the direction of the arrangement is 90 ° difference between both substrates, the entire molecular array is arranged so that there is a continuous 90 ° change between the two substrates, and when the liquid crystal voltage is applied, the electric field is opposed. It is formed perpendicular to the two substrate surfaces.

However, the liquid crystal display of the TN structure has a chronic problem of narrowing the viewing angle.

The liquid crystal display device of the IPS mode which can form the counter electrode which was formed in the upper glass substrate in the lower glass substrate now and takes a horizontal electric field when an electric field is applied and can ensure a wide viewing angle is proposed.

As shown in FIG. 1, the liquid crystal display of the IPS mode is formed on the same surface as the gate line 2A and the gate line 2A in the row direction for scanning an image on the lower glass substrate 1. The counter electrode 2B is spaced apart by a predetermined distance. The counter electrode 2B serves as a storage capacitor for maintaining the liquid crystal for a predetermined time, and is formed to have a □ -shape so as to define the shape of the unit cell. Although not shown in the drawings, a gate insulating film (not shown) is formed on the resultant to form electrical insulation between the lower gate line 2A and the materials to be formed later, and the gate line 2A is formed. The semiconductor layer 4 serving as a channel of the thin film transistor is formed on a predetermined portion of the gate insulating film. The data line 5A and the pixel electrode 5B are formed on the same plane, and the data line 5A intersects the gate line 2A vertically and is integrated with the data line 5A. 5A-1 overlaps a predetermined portion with the semiconductor layer 4 on the gate line 2A, and the pixel electrode 5B has an I-shape so that the space portion of the counter electrode 2B formed in a □ -shape is vertically divided. Is formed. The corner portion adjacent to the semiconductor layer 4 in this rectangular pixel electrode 5B extends to partially overlap the semiconductor layer 4 to become the drain electrode 5B. Here, reference numeral 100 denotes a surface through which light is transmitted when light is incident from a backlight (not shown) provided below.

As described above, in the liquid crystal display of the IPS mode in which no electrode is formed on the upper substrate, a parallel electric field is induced between the counter electrode 2B and the pixel electrode 5B, as shown in FIG. 2, to secure a wide viewing angle. Here, reference numeral 6 denotes a first polarizing plate for polarizing light at the bottom of the lower glass substrate, 10 is an upper substrate, 11 is a second polarizing plate formed on the back of the upper substrate, and 12 is between the upper substrate and the lower substrate. It is a liquid crystal interposed in.

However, the liquid crystal display device as described above has a rubbing process for aligning liquid crystals in a predetermined direction, high pressure static electricity is generated when the polarizer is attached, or a peeling layer for peeling the user to use a protective film attached to the upper part of the polarizer. As the balance of charges due to the escape of free electrons present is broken, electrostatic charges are generated on the outer glass substrate surface, thereby generating static electricity.

In particular, in the IPS mode in which the conductor is not provided on the upper substrate, the back surface of the upper substrate and the contact with the static electricity generating material may cause the static electricity to not easily disappear and remain.

In this case, in the IPS mode inducing a horizontal electric field, a vertical electric field is formed between the static electricity generating portion and the electrode region of the lower substrate, as shown in FIG.

For this reason, parallel electric field is induced and the drive itself of the original IPS mode which functions as an optical switch is disabled, and the display function of a liquid crystal display element is reduced.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of effectively leaking static electricity when static electricity is generated in the liquid crystal display device in the IPS mode.

Moreover, another object of this invention is to provide the liquid crystal display element which can improve the display function of the liquid crystal display element of IPS mode.

1 is a plan view of a liquid crystal display device in a general IPS mode.

2 is a cross-sectional view schematically showing a liquid crystal display device in a general IPS mode.

3 is a cross-sectional view of a liquid crystal display device in which static electricity is generated on the liquid crystal display device in the IPS mode, and a vertical electric field is formed.

4 is a cross-sectional view of the liquid crystal display of the IPS mode according to an embodiment of the present invention.

5 is a plan view showing a structure for preventing static electricity according to the present invention.

6 is a cross-sectional view of a liquid crystal display device in IPS mode according to another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

20: lower substrate, 21: first polarizing plate, 22: pixel electrode, 23: counter electrode, 25: liquid crystal, 30: upper substrate, 31: first transparent conductive film, 31-1: second transparent conductive film, 32: Second polarizer

In order to achieve the above object of the present invention, the liquid crystal display device of the present invention is a thin film transistor formed at the intersection of the gate line, the data line perpendicular to the gate line, the gate line and the data line, A liquid crystal display device formed on a same lower substrate of a pixel electrode connected to a drain electrode of a counter electrode and a counter electrode positioned at a distance separated by an area through which light is transmitted from the pixel electrode, the lower substrate comprising: a lower substrate; A first polarizer formed on a rear surface of the lower substrate; An upper substrate facing the lower substrate; An antistatic conductive film formed on the upper substrate; And a second polarizing plate formed on the upper substrate on which the conductive film is formed.

In addition, a liquid crystal display device according to another embodiment of the present invention includes a gate line, a data line perpendicular to the gate line, a thin film transistor formed at an intersection of the gate line and the data line, a drain electrode of the thin film transistor, A liquid crystal display device formed on a same lower substrate of a pixel electrode connected thereto and a counter electrode positioned at a distance separated by an area through which light passes through the pixel electrode, the liquid crystal display device comprising: a lower substrate; A first antistatic conductive film formed on a rear surface of the lower substrate; A first polarizing plate formed under the first antistatic conductive film; An upper substrate facing the lower substrate; A second antistatic conductive film formed on the upper substrate and connected to the first antistatic conductive film; And a second polarizing plate formed on the upper substrate on which the conductive film is formed.

According to the present invention, a transparent conductive film is formed on the upper substrate to effectively leak the generated static electricity, thereby improving the display function of the liquid crystal display element.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a cross-sectional view of the liquid crystal display device of the present invention, and FIG. 4 is a plan view of the antistatic transparent conductive film of the present invention.

As shown in FIG. 4, in the liquid crystal display of the present invention, reference numeral 20 denotes a lower substrate, 21 denotes a first polarizing plate for polarizing light incident on the lower substrate, and 22 denotes a pixel formed on the lower substrate. It is an electrode, 23 represents a counter electrode, 25 represents a liquid crystal. Reference numeral 30 denotes an upper substrate, 31 denotes an antistatic conductive film on the upper substrate, 32 denotes a second polarizing plate on the antistatic conductive film, and 33 denotes a liquid crystal interposed between the upper substrate and the lower substrate. Indicates.

On the lower substrate 20, a gate line (not shown), a data line (not shown) perpendicularly intersecting with the gate line, and a thin film transistor formed at an intersection point of the gate line and the data line are formed in a known manner. The counter electrode 23 is formed at a position spaced apart from the pixel electrode 22 and the pixel electrode 22 which share the drain of the thin film transistor by a predetermined interval. Here, the pixel electrode 22 and the counter electrode 23 are made of an opaque metal film, and when a predetermined voltage is applied to the pixel electrode 22 and the counter electrode 23, the pixel electrode 22 and the counter electrode 23 are formed. The upper liquid crystal is operated so that a parallel electric field is formed between the pixel electrode 2 and the counter electrode 23.

In addition, a conductive film 31 is formed on the upper substrate 30 facing the lower substrate 20 to prevent static electricity from being generated. This conductive film is preferably a transparent conductive film, for example, an indium tin oxide (ITO) material. Here, the conductive film 31 may be formed on the entire surface of the upper substrate 30, and in order to maximize the transmittance of light, as shown in FIG. 5, in the lower substrate 20, a surface through which light is transmitted ( The pattern corresponding to the opening 200 is patterned to be open.

A second polarizing plate 32 is formed on the conductive film 31 to deflect the light passing through the lower substrate in a predetermined direction.

This transparent conductive film 31 serves as a floating ground, thereby weakening the static electricity generated on the upper substrate surface.

FIG. 6 is a cross-sectional view of a liquid crystal display device according to another exemplary embodiment of the present invention. As shown in FIG. 5, not only the upper substrate 30 and the second polarizer 32, but also the lower substrate 20 and 1 The transparent conductive films 31-1 are also interposed between the polarizing plates 21, and the upper and lower transparent conductive films 31 and 31-1 are connected with the conductive film 40 or a conductor connector to equipotentially. To form. This suppresses dislocation formation between the upper and lower plates, thereby preventing static electricity. In this case, the lower conductive layer 31-1 may also have a structure that is patterned to expose a portion through which light passes.

As described above in detail, according to the present invention, a transparent conductive film for preventing static electricity is formed between the upper substrate and the polarizing plate on the upper substrate or between the lower substrate and the lower substrate, thereby effectively removing the generated static electricity, Generation of the liquid crystal display device with improved display function.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (12)

A lower substrate having a pixel electrode and a counter electrode positioned at a distance separated by an area through which light is transmitted from the pixel electrode; An upper substrate facing the lower substrate; And an antistatic conductive film formed on the upper substrate. The liquid crystal display device according to claim 1, wherein the antistatic conductive film has an open surface through which light is transmitted. The liquid crystal display device according to claim 1 or 2, wherein the antistatic conductive film is a transparent conductive film. The liquid crystal display device of claim 3, wherein the antistatic conductive film is an indium tin oxide (ITO) film. The liquid crystal display device of claim 1, wherein an upper polarizer is disposed on the antistatic conductive film. The liquid crystal display of claim 1, wherein an antistatic conductive film is provided on a lower surface of the lower substrate to prevent static electricity generated on the lower substrate. A lower substrate having a pixel electrode and a counter electrode positioned at a distance separated by an area through which light is transmitted from the pixel electrode; A first antistatic conductive film formed on a rear surface of the lower substrate; An upper substrate facing the lower substrate; And a second antistatic conductive film formed on the upper substrate and connected to the first antistatic conductive film. 8. The liquid crystal display device according to claim 7, wherein the first and second antistatic conductive films have an open surface through which light is transmitted. The liquid crystal display device according to claim 7 or 8, wherein the antistatic conductive film is a transparent conductive film. The liquid crystal display device according to claim 9, wherein the antistatic conductive film is an ITO film. The liquid crystal display device according to claim 7, wherein the first and second antistatic conductive films are connected by a conductive film. 8. The liquid crystal display device according to claim 7, wherein a lower polarizing plate and an upper polarizing plate are respectively provided below the first antistatic conductive film and above the second antistatic conductive film.